package unit_6;
import java.util.Scanner;
public class Demo04 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String str = sc.next();
        str = str.toLowerCase();
        char[] s = str.toCharArray();
        int cnt = 0;
        for(char i: s){
            if(i >= 'a' && i <= 'z')
                cnt++;
        }
        System.out.println(cnt);
    }
}
